Node.js TextEncoder

The TextEncoder is an interface that takes a stream of code points as input and emits a stream of encoded UTF-8 codes. This is provided in NodeJS as an implementation of the WHATWG Encoding Standard 'TextEncoder' API. All instances of TextEncoder only support UTF-8 encoding.

UTF-8: It is an encoding mechanism that encodes in multiple 8 bits. It is capable of encoding all 1,112,064 characters in 4 bytes, each of 8 bits. The first 128 characters match the ASCII mapping.

Import:

var util = require('util');

Syntax:

util.TextEncoder( );

Constructor:

• TextEncoder( ): This method will return an new object of TextEncoder class which can generated encoding of UTF-8 format.

Properties:

The TextEncoder class does not inherit any property. Only one property is defined which is:

• TextEncoder.prototype.encoding: It is a read-only property that returns a string of the name of the encoding used by the object. It always returns UTF-8.

Functions:

• encode(string): returns Uint8Array from a 'string'.
• encodeInto(string, dest): takes two parameters Input first is the input string and the second is the output array. It encodes 'string' into 'dest' that must be Uint8Array.

Return Value: Returns an array corresponding to encoding format containing code points representing input.

Example 1: We will encode and save the output in a local variable and print it on the console to check the encoded value. Create a file index.js and write the below code:

var util = require('util');
let encoder = new util.TextEncoder();
let uint8Array = encoder.encode("Hello");
console.log(uint8Array);

Steps to run the application: Write the below command in the terminal to start the server:

node index.js

Output:

Uint8Array [ 72, 101, 108, 108, 111 ]

Example 2: We will now encode the string into an output array bigger than the size of the input to see how they function encodes. Create a file index.js and write the below code:

var util = require('util');
let encoder = new util.TextEncoder();
let src = "Hello";
let uint8Array = new Uint8Array(10);
encoder.encodeInto(src, uint8Array);
console.log(uint8Array);

Steps to run the application: Write the below command in the terminal to start the server:

node index.js

Output:

Uint8Array(10) [ 72, 101, 108, 108, 111,0,   0,   0,   0,   0]

Browser Compatibility:

Reference: https://nodejs.org/api/util.html#class-utiltextencoder